The minimization of vibration in disk drives assemblies is the source of much continuing effort in the disk drive industry. The basic problem is how to rigidly mount a disk drive assembly in an enclosure, such as a rack system, to help minimize vibration problems, while simultaneously allowing safe, easy removal and replacement of the disk drive assembly. In the past, the disk drives were bolted to the enclosures and were isolated from the enclosures with bushings or grommets. This vibration damping structure worked for disk drives that were less susceptible to vibration problems than the disk drives of the present, but seriously impeded the ability to easily remove and replace the disk drive assemblies.
Presently, disk drives are becoming smaller, faster and lighter, with higher track densities. Due to these changes, it is much easier to disturb the disk drives, which causes several types of disk errors. In addition, in the effort to create the smaller disk drives, vibration mitigation in the disk drive housing has not been emphasized. Thus, as the areal density becomes greater, the detrimental effect of vibration increases. Further, efforts at designing damping systems in the drive housing has been deemphasized because it was found that each damping system had to be tuned to the particular drive system.
Vibration causes many problems, including but not limited to increasing retry rates, which devastates system performance. In addition, as drive RPMs become higher, the vibration problems are accordingly increased. Also, the increase in track densities have forced an even greater burden of vibration attenuation to the systems integration level.
In order to minimize the detrimental effects of vibration on drive performance, several features can be designed into the rack system to attempt to eliminate or dampen vibration sources and transmission. Vibration arresting measures can be implemented where the rack system is mounted to the floor, where each rack is attached to the rack system, where the drive housing is attached to the shelf, and inside the drive housing itself. As described above, vibration can cause serious performance problems, and even permanent damage, to an individual drive or a group of drives. The most efficient manner of protecting the customers investment with respect to vibration attenuation directs vibration reduction efforts to the interaction of the disk drive and the shelf upon which it is positioned.
In order to minimize the transmissibility of the vibration path to the disk drive and thus to the heads, one must either dampen the structure to lower the transmissibility, or attempt to avoid the cause of vibrations all together. Offending vibrations can come from adjacent drives, adjacent shelves, fans, floor movement, outside traffic, HVAC systems, etc.
It is to overcome the shortcomings in the prior art that the present invention was developed.